Filter device and measuring apparatus

Abstract

A filter device through which a fluid containing a target substance and a coarse substance larger than the target substance is passed to selectively collect the target substance from the fluid. The filter device includes a prefilter that removes the coarse substance and a collection filter that collects the target substance. The prefilter and the collection filter are arranged in series such that the fluid passes through the prefilter and then through the collection filter. The prefilter includes a cavity arrangement structure having a pair of opposing main surfaces and a plurality of cavities extending through both main surfaces.

1 . A filter device through which a fluid containing a target substance and a coarse substance larger than the target substance can be passed to selectively collect the target substance from the fluid, the filter device comprising:
 a prefilter constructed to remove the coarse substance from the fluid; and   a collection filter constructed to collect the target substance from the fluid,   the prefilter and the collection filter being arranged in series such that the fluid passes through the prefilter and then through the collection filter,   the prefilter comprising a cavity arrangement structure having a pair of opposing main surfaces and a plurality of cavities extending through the pair of opposing main surfaces.   
     
     
         2 . The filter device according to  claim 1 , wherein a percentage of an open area of the cavities to an area of each main surface of the prefilter including the cavities is 3% to 80%. 
     
     
         3 . The filter device according to  claim 2 , wherein the cavities have an aspect ratio T/D of less than 3, where T is a thickness of the cavity arrangement structure, and D is an opening size of the cavities. 
     
     
         4 . The filter device according to  claim 1 , wherein a percentage of an open area of the cavities to an area of each main surface of the prefilter including the cavities is 10% to 60%. 
     
     
         5 . The filter device according to  claim 4 , wherein the cavities have an aspect ratio T/D of less than 3, where T is a thickness of the cavity arrangement structure, and D is an opening size of the cavities. 
     
     
         6 . The filter device according to  claim 1 , wherein the cavities have an aspect ratio T/D of less than 3, where T is a thickness of the cavity arrangement structure, and D is an opening size of the cavities. 
     
     
         7 . The filter device according to  claim 1 , wherein the collection filter is a membrane filter. 
     
     
         8 . The filter device according to  claim 1 , wherein the collection filter comprises a stack of arrangement structures shifted relative to each other, each arrangement structure having a pair of opposing main surfaces and a plurality of cavities extending through the pair of opposing main surfaces. 
     
     
         9 . The filter device according to  claim 1 , wherein the cavities are periodically arranged. 
     
     
         10 . The filter device according to  claim 1 , wherein a surface of the cavity arrangement structure is at least partially made of a conductor. 
     
     
         11 . The filter device according to  claim 1 , wherein the entire cavity arrangement structure is made of a conductor. 
     
     
         12 . The filter device according to  claim 1 , wherein the collection filter is modified to adsorb the target substance. 
     
     
         13 . The filter device according to  claim 1 , wherein the prefilter is thicker than the collection filter. 
     
     
         14 . The filter device according to  claim 13 , wherein the collection filter is modified to adsorb the target substance. 
     
     
         15 . The filter device according to  claim 14 , wherein pores of the collection filter are sized to allow the target substance to pass therethrough. 
     
     
         16 . A measuring apparatus comprising:
 the filter device according to  claim 1 ; and   a measuring mechanism that irradiates the collection filter with electromagnetic radiation after the collection filter collects the target substance and that measures the amount of target substance based on the electromagnetic radiation characteristics of the collection filter.